Kolleru Lake: a perfect case study for students of biodiversity

‘Reasons for disappearance and reappearance of grey pelicans still not known’

The disappearance and re-appearance of grey pelicans from Kolleru Lake, once the largest freshwater lake in the country, is a textbook case for students of biodiversity.

The magnificent bird that needs large amounts of fish was nesting in Kolleru Lake from time immemorial.

Gordon Mackenzie, Collector of Krishna district, in his manual dated April 16, 1883 mentioned colonies of Pelican in Kolleru and the protection given to them by villagers who considered them harbingers of ‘good fortune’.

Though Mackenzie mentioned the birds in his manual of Krishna district which then included parts of the present day West Godavari and Guntur districts, it was a report by ornithologist Neelakantham to the Journal of the Bombay Natural History Society about the Kolleru pelicanry that led to its recognition as the world’s largest pelicanry in 1949. Mr Neelakantham said there were 4,000 nests in Kolleru pelicanary at that time.

After a hue and cry by environmentalists about the neglect of the unique freshwater lake the Andhra Pradesh Government declared the lake and all areas within a radius of 20 miles as protected area in 1963.

But for reasons not known even to the ornithologists the pelicans stopped coming to the lake from 1974. While some environmentalist believed that the large birds were killed by poachers and sold as chicken in Bhimavaram, a fast growing town, some others dispute it saying that it was unlikely because the flesh of the bird was not considered a delicacy like that of wild duck. The advent of aquaculture, continuous human disturbance, and wanton destruction of nesting canopies were cited as reasons for the disappearance of the large birds.

Survey

A survey of avian fauna made by Osmania University Professor Ramana Rao and his team in the late 70s did not mention pelicans in the list of 188 local and migratory birds sighted in Kolleru. Meanwhile, the spread of aquaculture frightened of many others and birds such as teals, pouchards and pintails which visited the lake in thousands stopped coming in such large numbers.

The exhaustive list made by the Osmania University team did not mention the pelicans, painted storks, gray headed lapwings, Gray Lag Goose and the spoonbilled sandpiper that have been subsequently sighted in the Lake. The pelicans “miraculously” returned in November 2006 a few months after the demolition of the fish tanks that spread all over the lake. The demolition of the fish tanks did not happened over night. The preliminary notification to declare the lake as a wildlife sanctuary was issued in 1995 under section 18 of the Wildlife Protection Act. In 1999 the lake was declared a Wildlife Sanctuary under Section 23 of the Act.

Former Assistant Conservator of Forest and authority on the birds of Kolleru Lake P.Gracious said he had found that 10 species of birds that were not in the list made by Osmania University team had returned to the lake the best example was the pelican. The painted storks were also seen in hundreds.